Power adapters are essential for many electronic devices such as notebook computers or mobile phones. Generally, the user may simply plug an AC plug of a power adapter into an AC wall outlet commonly found in most homes or offices so as to receive an AC voltage. The power adapter will convert the AC voltage into a regulated DC output voltage for powering the electronic device and/or charging a battery built-in the electronic device.
Referring to FIG. 1(a), a schematic perspective view of a conventional power adapter to be used in a notebook computer is illustrated. The power adapter of FIG. 1(a) comprises a main body 11, an AC power cable 12, an AC inlet 13, a DC power cable 14 and a DC plug 15. The AC inlet 13 is connected to the input terminal of the main body 11 for receiving an AC voltage from an external power source. The DC plug 15 is connected to the output terminals of the main body 11. After the DC plug 15 is inserted into a power receiving slot 161 of an electronic device 16 such as a notebook computer, the AC voltage transmitted from the external power source is converted by the circuitry of a printed circuit board inside the main body 11 into regulated DC output voltages and transmitted to the electronic device 16 through the DC power cable 14 and the DC plug 15.
Please refer to FIG. 1(b), which is a partial schematic exploded view of the power adapter of FIG. 1(a). The power adapter includes an upper cover 111, a lower cover 112 and a circuit board 113. A closed space is defined between the upper cover 111 and the lower cover 112 for accommodating therein the circuit board 113. An end of the DC power cable 14 includes a coupler head 141 and two conductive terminals 142 serving as positive and negative electrodes. For assembling the power adapter 11, the circuit board 113 is received in the lower cover 112, and then the conductive terminals 142 of the DC power cable 14 are coupled to the circuit board 113. Then, the upper cover 111 is combined with the lower cover 112 by using for example an ultrasonic welding operation or a fastening operation. When the upper cover 111 and the lower cover 112 are combined together, the first notch 1110 of the upper cover 111 and the second notch 1120 of the lower cover 112 are sheathed around a receiving portion 143.
By means of the power adapter 11, the regulated DC output voltages will be transmitted to the electronic device 16 through the DC power cable 14 and the DC plug 15. However, a special consideration should be taken to secure the DC power cable 14. As shown FIG. 1(c), a strap 17 is used to secure a bundled DC power cable 14 for storage. Under this circumstance, a bent portion 18 is readily formed at the interface between the output terminals of the main body 11 and the DC power cable 14. Generally, the bundled DC power cable 14, which is suspended over the main body 11, results in an inferior appearance and occupies a lot of space.
In views of the above-described disadvantages resulted from the prior art, the applicant keeps on carving unflaggingly to develop a power adapter having a detachable power cable coupler head according to the present invention through wholehearted experience and research.